JP2014148567A - Resin composition and near-infrared ray cut filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition prepared using a squarylium compound with less absorption in a visible range (400-500 nm), and also provide a near-infrared ray cut filter prepared using the resin composition, particularly a near-infrared ray cut filter for an image pickup device such as CCD and CMOS.SOLUTION: A resin composition is composed of a squarylium compound represented by the formula (1) and a resin, wherein groups Arand Arrepresent a substituent comprising a condensed ring of a nitrogen-containing five-membered ring having a substituent such as a benzyl group at a nitrogen atom and benzene or naphthalene.

Description

  The present invention relates to a resin composition containing a squarylium compound, and a near infrared filter (optical filter) using the same.

  Image sensors such as CCDs and CMOSs used in digital cameras have a spectral sensitivity over the near infrared region from the visible region to near 1100 nm, whereas the human eye has a wavelength around 400 nm to 700 nm. Can feel the light. Therefore, since there is a large difference in spectral sensitivity between the image sensor and the human eye, it is necessary to provide a near-infrared cut filter that absorbs the near-infrared region in front of the image sensor to correct the visual sensitivity of the human eye. It is known.

  As a near-infrared cut filter used for an image sensor, a glass filter in which CuO is added to phosphate glass is known as described in Patent Document 1. However, the glass having the near infrared absorption ability is very expensive. Moreover, since it is glass, there exists a problem in workability, and the freedom degree of design of an optical characteristic is also narrow. In addition, therefore, the development of filters and compositions (which may include thermoset or photocurable compositions) incorporating new near infrared absorption capabilities has been desired.

  Although the thing of patent documents 2-4 is known as an organic pigment | dye which has near-infrared absorptivity, Although the cyanine pigment | dye and diimonium pigment | dye whose counter ion is a hexafluoroantimonate ion were mainly used especially. Since antimony-containing compounds fall under the category of deleterious substances, compounds that do not contain heavy metals have been desired in recent years, particularly in the industrial field where the use of heavy metals and the like is regulated, particularly in the field of electrical materials. Patent Document 4 describes compounds that do not contain heavy metals, but these compounds have insufficient solubility in solvents used for coating and the like. A compound with improved processability and good processability is described in Patent Document 5, but there is a strong demand for development of a dye compound having absorption in the visible region and having good visible light transmittance.

  In order to solve these problems, as described in Patent Document 5, a dye that absorbs a region of 650 nm to 750 nm, and a near-infrared absorbing composition characterized by containing the dye have been proposed. But it's not enough.

  On the other hand, a squarylium compound as described in Non-Patent Document 1 is an example of a dye compound having a good visible light transmittance. However, the maximum absorption wavelength is short for use in a near-infrared cut filter and cannot be said to be sufficient. .

  From such a background, in recent years, a near-infrared absorbing compound with little visible light absorption, a resin composition using the compound, and a near-infrared cut filter, particularly absorption at 400 nm to 500 nm is less and absorption is in the region of 650 nm to 750 nm. There is a strong demand for the development of near-infrared absorbing dyes for image sensors such as CCD and CMOS, and near-infrared cut filters using the dyes.

JP 62-128943 A JP 2000-81511 A Japanese Patent Publication No. 5-37119 Japanese Patent No. 3045404 JP 2006-343631 A JOEHANDBOOK 2 ABSORPTION SPECTRA OF DYES FOR DIODE LASTERS p. 51

  An object of the present invention is to provide a resin composition using a squarylium compound with little absorption in the visible region, particularly 400 nm to 500 nm, and a near-infrared cut filter with little visible region absorption.

  As a result of intensive studies, the present inventors have solved the above-mentioned problems by a resin composition of a specific squarylium compound represented by the following formula (1) and a near-infrared cut filter. The present invention was completed.

（式中、基Ａｒ^１、Ａｒ^２はそれぞれ独立に下記の式（２）〜（４）のいずれかの置換基を表す。ただし、Ａｒ^１、Ａｒ^２が共に（２）の場合は除く）

（式（２）〜（４）中、基Ａは独立に下記の式（５）〜（８）のいずれかの置換基を表す。）

（式（５）中、ｎは０〜３の整数を表す。）

（式（８）中、ｍは０〜３の整数を表す。）
（２）式（１）において、基Ａｒ^１、Ａｒ^２が共に式（３）である化合物を含有することを特徴とする（１）に記載の樹脂組成物、
（３）式（３）において、基Ａが式（５）である化合物を含有することを特徴とする（１）または（２）に記載の樹脂組成物、
（４）（３）に記載の樹脂組成物を用いた近赤外線カットフィルタ、
（５）（４）に記載の近赤外線カットフィルタを用いた撮像素子、
に関する。 That is, the present invention
(1) A resin composition comprising a compound represented by the following formula (1) and a resin:

(In the formula, groups Ar ¹ and Ar ² each independently represent a substituent of any one of the following formulas (2) to (4), except when both Ar ¹ and Ar ² are (2)).

(In the formulas (2) to (4), the group A independently represents any substituent of the following formulas (5) to (8).)

(In formula (5), n represents an integer of 0 to 3)

(In formula (8), m represents an integer of 0 to 3.)
(2) The resin composition according to (1), wherein in the formula (1), the groups Ar ¹ and Ar ² both contain a compound represented by the formula (3),
(3) The resin composition according to (1) or (2), wherein in the formula (3), the group A contains a compound represented by the formula (5),
(4) A near-infrared cut filter using the resin composition according to (3),
(5) An image sensor using the near-infrared cut filter according to (4),
About.

  INDUSTRIAL APPLICABILITY According to the present invention, a squarylium compound resin composition that absorbs less in the visible region, particularly 400 nm to 500 nm, and a near-infrared cut filter that uses the visible region that absorbs less visible region, particularly near-infrared rays for image sensors such as CCD and CMOS. A cut filter could be provided.

The present invention will be described in detail.
In formula (1), the groups Ar ¹ and Ar ² represent formulas (2) to (4), preferably formula (3).

  In formula (5), n represents an integer of 0 to 3, preferably 0 to 1, and more preferably 1. Moreover, in Formula (8), m represents the integer of 0-3, Preferably it is 3.

Of the groups Ar ¹ , Ar ² , A, n, and m, a compound in which preferable ones are combined is more preferable, and a compound in which more preferable ones are combined is more preferable. The same applies to combinations of preferable and more preferable ones.

The squarylium compound represented by the above formula (1) is produced by various methods. For example, Dyes and Pigments Volume 95, Issue 3, 2012, p, regardless of whether the groups Ar ¹ and Ar ² are the same. . 657-670 (Reference Document 1).

  The infrared cut filter (optical filter) using the resin composition of the present invention containing a squarylium compound may be one in which a resin layer containing a squarylium compound is provided on a substrate, or the substrate itself contains a squarylium compound. The layer which consists of a resin composition (or its hardened | cured material) may be sufficient. The substrate is not particularly limited as long as it can be generally used for an optical filter, but a resin substrate is usually used. The thickness of the layer is usually about 0.1 μm to 10 mm, but can be appropriately determined according to the purpose such as the near infrared cut rate.

  Moreover, the content rate of the squarylium compound used for the resin composition of this invention can also be suitably determined according to the target near-infrared cut rate. Examples of the resin base material used include polyethylene, polycycloalkane, polystyrene, polyacrylic acid, polyacrylic acid ester, polyvinyl acetate, polyacrylonitrile, polyvinyl chloride, polyvinyl fluoride, and other vinyl compounds, and their Addition polymer of vinyl compound, polymethacrylic acid, polymethacrylic acid ester, polyvinylidene chloride, polyvinylidene fluoride, polyvinylidene fluoride, vinylidene fluoride / trifluoroethylene copolymer, vinylidene fluoride / tetrafluoroethylene copolymer, Vinyl compounds such as vinylidene cyanide / vinyl acetate copolymers or copolymers of fluorine compounds, fluorine-containing resins such as polytrifluoroethylene, polytetrafluoroethylene, and polyhexafluoropropylene, nylon 6, and nylon Polyamide 66 or the like, polyimides, polyurethanes, polypeptides, polyesters such as polyethylene terephthalate, polycarbonate, polyether polyoxymethylene or the like, epoxy resins, polyvinyl alcohol, polyvinyl butyral, and the like.

  Although it does not specifically limit as a method of producing the infrared cut filter (optical filter) of this invention, For example, the following well-known method can be utilized. 1) A method of kneading a squarylium compound into a resin to obtain a resin composition of the present invention and thermoforming it to produce a resin plate or film. 2) Presence of a polymerization catalyst comprising a squarylium compound and a resin monomer or a prepolymer of the resin monomer. A method for producing a resin plate or film by cast polymerization below, 3) a method for producing a coating containing a squarylium compound, and coating the transparent resin plate, transparent film or transparent glass plate, 4) a squarylium compound and a resin ( And a method of producing a laminated resin plate, a laminated resin film, or a laminated glass plate using a composition containing an adhesive).

  In the method 1), the processing temperature, filming (resin plate) conditions, etc. are slightly different depending on the resin to be used. Usually, a squarylium compound is added to, for example, the above-mentioned base resin powder or pellet, and the temperature is 150 to 350 ° C. And a method of forming a resin plate by heating and dissolving, or a method of forming a film (resin plate) with an extruder. The addition amount of the squarylium compound varies depending on the thickness, absorption strength, visible light transmittance, etc. of the resin plate or film to be produced, but is usually about 0.01 to 30% by mass, preferably 0, based on the mass of the base resin. About 0.03 to 15% by mass is used.

  In the method of 2), a squarylium compound and a resin monomer or a prepolymer of a resin monomer are injected into a mold in the presence of a polymerization catalyst to form a resin composition of the present invention, which is reacted and cured, or gold There is a method in which it is cast into a mold and solidified until it becomes a hard product in the mold. Many resins can be molded by this method, and examples of such resins include (meth) acrylic resins, diethylene glycol bis (allyl carbonate) resins, epoxy resins, phenol-formaldehyde resins, polystyrene resins, and silicon resins. . Among them, the casting method by bulk polymerization of methyl methacrylate, which can obtain an acrylic sheet excellent in hardness, heat resistance, and chemical resistance, is preferable. As the polymerization catalyst, known radical thermal polymerization initiators can be used, for example, peroxides such as benzoyl peroxide, p-chlorobenzoyl peroxide, diisopropyl peroxycarbonate, and azo compounds such as azobisisobutyronitrile. It is done. The amount used is generally from 0.01 to 5% by weight, based on the total amount of the mixture. The heating temperature in the thermal polymerization is usually 40 to 200 ° C., and the polymerization time is usually about 30 minutes to 8 hours. In addition to thermal polymerization, a method of photopolymerization by adding a photopolymerization initiator or a sensitizer can also be employed.

  The method of 3) includes a method of dissolving the squarylium compound in a binder resin and a solvent to form a paint (resin composition of the present invention), a method of dispersing the squarylium compound into fine particles in the presence of the resin, and forming a water-based paint. is there. In the former method, for example, aliphatic ester resin, acrylic resin, melamine resin, urethane resin, aromatic ester resin, polycarbonate resin, polyvinyl resin, aliphatic polyolefin resin, aromatic polyolefin resin, polyvinyl alcohol resin, polyvinyl modification Resins or the like or copolymer resins thereof can be used.

  As the solvent, a halogen-based, alcohol-based, ketone-based, ester-based, aliphatic hydrocarbon-based, aromatic hydrocarbon-based, ether-based solvent, or a mixed solvent thereof can be used. The concentration of the squarylium compound varies depending on the thickness of the coating to be produced, the absorption strength, and the visible light transmittance, but is generally about 0.1 to 30% by mass with respect to the binder resin. The paint thus obtained can be coated on a transparent resin film, transparent resin plate, transparent glass or the like with a spin coater, bar coater, roll coater, spray or the like to obtain a near infrared absorption filter.

  In the method 4), 0.1% of squarylium compound is added to a known transparent adhesive for laminated glass such as silicon-based, urethane-based, acrylic-based resin, polyvinyl butyral adhesive, ethylene-vinyl acetate-based adhesive, and the like. An optical filter is prepared by bonding transparent resin plates, resin plates and resin films, resin plates and glass, resin films, resin films and glass, and glasses using a resin added to about 30% by mass. In addition, when kneading and mixing by each method, usual additives used for resin molding such as an ultraviolet absorber and a plasticizer may be added.

  The near-infrared cut filter of the present invention may use only one or two or more squarylium compounds of the above formula (1) as a near-infrared absorbing compound, but these compounds are further used to broaden the absorption wavelength range. Other near infrared absorbing compounds may be used in combination. Examples of other near infrared absorbing compounds that can be used in combination include metal complex compounds such as cyanine compounds, diimonium compounds, phthalocyanine compounds, and nickel dithiol complexes. When other near infrared ray absorbing compounds that can be used in combination with these are cationic, the counter anion may be a tris (halogenoalkylsulfonyl) methide anion. As the other near-infrared absorbing compound, a diimonium compound is particularly preferable, and a counter anion of the diimonium compound is preferably a tris (halogenoalkylsulfonyl) methide anion.

  Examples of the near-infrared absorbing compound of inorganic metal that can be used in combination include, for example, copper compounds such as metallic copper or copper sulfide, copper oxide, a mixture mainly composed of zinc oxide, a tungsten compound, and a mixture mainly composed of titanium oxide. Is mentioned.

  The optical filter of the present invention for absorbing near infrared rays is used not only for imaging device applications and display front plates, but also for filter films that need to cut near infrared rays, such as heat insulating films, optical products, sunglasses, etc. I can do it.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the examples. Unless otherwise specified, “part” and “%” in the text are based on mass. Spectral characteristics were measured in methanol using an ultraviolet-visible spectrophotometer UV-3150 (manufactured by Shimadzu Corporation).

[Example 1]
A diallyl phthalate resin (Daiso Co., Ltd., trade name “Daiso Dup S”) was dissolved in chloroform so as to be 30% by mass to obtain a base solution. The squarylium compound (maximum absorption wavelength: 662 nm) represented by the following formula (9) synthesized in Reference 1 is added to the main agent solution so as to be 0.05% by mass with respect to the total mass of the main agent solution. Thus, a coating solution in which these were dissolved was obtained. This coating solution was dropped on a glass substrate placed on a spin coater, and the substrate surface was coated by rotating the substrate at 1000 rpm for 10 seconds, and then dried at 80 ° C. for 10 minutes to obtain an optical filter.

[Comparative Example 1]
Optical for comparison in the same manner as in Example 1, except that only 0.14% by mass of a cyanine compound (maximum absorption wavelength: 693 nm) represented by the following formula (10) synthesized with reference to Japanese Patent No. 4635007 is used. A filter was produced. This optical filter is referred to as Comparative Example 1.

  The optical characteristics of the optical filters obtained in Example 1 and Comparative Example 1 were evaluated by the following methods.

[optical properties]
Using the spectrophotometer, the absorbance of each optical filter of Example 1 and Comparative Example 1 was measured in the range of 200 to 1100 nm. The absorbance at the maximum absorption wavelength of the optical filter of Example 1 and Comparative Example 1 is A2, and the absorbance at the maximum absorption wavelength in the wavelength region of 400 nm to 500 nm is A1, and the ratio R (A2 / A1) of A1 and A2 is obtained. It was. The respective values are shown in Table 1.

  It can be said that the smaller the value of A1 with respect to A2, that is, the larger the value of R, the less the visible light absorption with respect to the infrared absorption, and the near-infrared cut filter having excellent transparency in the visible light region. From the results in Table 1, R in Comparative Example 1 showed a lower value than R in Example 1, indicating a result inferior as a near infrared cut filter.

  The resin composition of the present invention containing the squarylium compound represented by the above formula (1) and the near-infrared cut filter (optical filter) obtained by these have a near red color while ensuring a visible light region, particularly 400 nm to 500 nm. Since external light, particularly near-infrared light of 650 nm to 700 nm can be sufficiently shielded, it is very useful as an optical filter for various applications, particularly as a near-infrared cut filter (optical filter) for an image sensor such as a CCD or CMOS.

Claims (5)

A resin composition comprising a compound represented by the following formula (1) and a resin.

(In the formula, groups Ar ¹ and Ar ² each independently represent a substituent of any one of the following formulas (2) to (4), except when both Ar ¹ and Ar ² are (2)).

(In the formulas (2) to (4), the group A independently represents any substituent of the following formulas (5) to (8).)

(In formula (5), n represents an integer of 0 to 3)

(In formula (8), m represents an integer of 0 to 3.) ^2. The resin composition according to claim ¹ , wherein in the formula (1), the groups Ar ¹ and Ar ² both contain a compound represented by the formula (3). 3. The resin composition according to claim 1, wherein in the formula (3), the group A contains a compound represented by the formula (5). A near-infrared cut filter using the resin composition according to claim 3. An image sensor using the near-infrared cut filter according to claim 4.